Field Evaluation of Nitrogen and Zinc Rates in a Cotton/Corn Rotation

Friday, January 5, 2018: 9:15 AM
Salon J (Marriott Rivercenter Hotel)
Dr. M. Wayne Ebelhar , Mississippi State University
An interaction of nitrogen (N) rates and zinc (Zn) rates has been under investigation in both cotton and corn in a cotton/corn (1/1) rotation.  The studies are being conducted under irrigated conditions at the Delta Research and Extension Center near Stoneville, MS.  Zinc deficiencies have started appearing over the last few years and have warranted an investigation to try and remedy the problem.  Nitrogen rates applied to corn have ranged from 120 to 280 lb N/acre.  The initial application of 120 lb N/acre has been followed with 40, 80, 120, or 160 lb N/acre at the 5-6 leaf growth stage. Nitrogen rates in the cotton study has ranged from 30 to 120 lb N/ace with either 30 or 60 lb N/acre applied at planting with the remainder applied at pin-head square.  Zinc rates for both cotton and corn have been 0, 5, 10, and 15 lb Zn/acre applied as zinc sulfate dissolved in water and applied as a sidedressed application.  Yield results from the first two years of the studies will be presented along with soil test data.  Zinc levels in soils tend to be low and not easily detected when the fertilizer has been band-applied.